Supervisory control system for aircraft flight management during pilot command errors or equipment malfunction

ABSTRACT

A system and method for intervention control of an aircraft in the event of pilot command error whether voluntary or involuntary. Impending detection of a chaotic condition associated with a maneuvering aircraft enable early prediction and control of the aircraft where solutions based upon performance prediction are available. A further feature of the present intervention control of the aircraft enables an equipment malfunction detection signal substitution of a satisfactory equipment signal.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of application Ser.No. 09/538,046, filed Mar. 29, 2000, pending.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates generally to a flight safety system andmore particularly to a method and apparatus for preventing accidentsresulting from pilot command errors or equipment malfunctions during theflight of an aircraft.

[0004] 2. Description of the Prior Art

[0005] Heretofore, alarm systems have sounded to indicate that a majorproblem has occurred on the aircraft that the flight crew must attend toimmediately, e.g.:

[0006] a. The aircraft's speed has exceeded a predetermined safe machlevel, e.g. 0.86 mach.

[0007] b. Cabin pressure has fallen below acceptable levels.

[0008] c. The autopilot has become disconnected for reasons other thanpilot command.

[0009] d. Fire indication.

[0010] e. Improper take-off or landing configurations.

[0011] Heretofore, the pilot of the aircraft has been depended upon torespond to events a. through e.

[0012] Prior systems failures aboard the aircraft such as failure of theinstrument landing system, automatic braking system, autopilot etc. haveheretofore afforded the pilot of the aircraft no known remedy except tofly the aircraft with such systems inoperative.

BRIEF SUMMARY OF THE INVENTION

[0013] The present invention provides support services for equipmentaboard an aircraft normally heretofore available only at a groundservice facility.

[0014] Input signals from equipment aboard the aircraft are coupled viaa data link to corresponding ground equipment continuously maintained asa standard by e.g. the manufacturer. An equipment substitution signalcommands an output signal from the ground equipment standard to besubstituted for the equipment output signal aboard the aircraft. Theoutput signal transmitted from the ground equipment is an informationsignal transmitted over a data link reconditioned as required to theproper signal level required by the equipment aboard the aircraft. Anequipment substitution signal is generated in response to comparison ofthe aircraft equipment signal with the standard.

[0015] Failure of airborne equipment does not result in loss of thisequipment during flight thus handicapping the pilot in flight of theaircraft.

[0016] A further important feature of the system of the presentinvention is the provision for override of pilot control when a pilotcommand error is detected. A pilot command error may occur when anincorrect flight configuration and operating parameters are detectedwhether voluntary or involuntary. The present system provides immediateoverride should this be necessary in the event of pilot inability torespond through immediate voice communication where time permits. Thepresent ground system override permits a pilot at the ground stationthrough activated ground controls corresponding to the aircraft's flightcontrols to fly the aircraft. The pilot in command at the ground stationmay, instead of controlling the flight of the aircraft manually, utilizea flight control computer containing further flight control programmingnot available to the pilot flight control computer, e.g. containingprograms for flying the aircraft in rarely occurring emergencysituations such as loss of a functioning control surface where immediatecontrol signals are required in response to uncontrolled maneuvering ofthe aircraft which control signals are based upon understanding andcalculations of flow physics.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0017]FIG. 1 is a block diagram of an embodiment of the present systemshowing an aircraft under control of the present intervention controlsystem and a further aircraft transparent to the present interventioncontrol system;

[0018]FIG. 2 is exemplary of a comparator circuit utilized in thepresent intervention control system of FIG. 1 for a twin enginecommercial jet aircraft providing automatic back up in the event of apilot error;

[0019]FIG. 3 is illustrative of the present system ground equipmentsubstitution in the event of the presence of an equipment substitutionsignal representative of a corresponding equipment failure aboard anaircraft;

[0020]FIG. 4 is a diagram illustrative of normal configurations atdifferent altitudes utilized under normal conditions; and,

[0021]FIG. 5 is illustrative of an exemplary type of flight controlsystem for flight control based upon input flight control signalinformation received from an aircraft data link to a ground stationwhich information signals are representative of abnormal maneuver of anaircraft during an emergency condition.

DETAILED DESCRIPTION OF THE INVENTION

[0022] Introduction

[0023] Transmission of digital data between each commercial aircraft andthe proper airline flight operations department occurs today throughACARS (Aircraft Addressing and Reporting System) developed by ARINC(Aeronautical Radio Inc.). Such data presently includes aircraftidentification, fuel data, engine performance data, etc. Development ofbroadband communications between aircraft, in flight satellitecommunications links, H.F. (high frequency) links, etc. are expandingthe potential for increased data transfer and will reduce the need foran extensive network of ground stations. These efforts at improving datatransfer rates will facilitate increased use of systems such ashereinafter described. Close monitoring of aircraft performance andcontrol of the aircraft under emergency conditions based upon early dataas hereinafter described will increase the probability of recovery undersuch conditions. Improved support functions for aircraft in flight willresult from early detection of equipment malfunction and replacement ofcorrected output signals for the malfunctioning equipment.

[0024] Turning now to the system of FIG. 1, there is shown an aircraft Bhaving a flight control system 20 which includes a flight controlcomputer which interfaces with a number of aircraft systems, variousaircraft sensors, e.g. aileron position sensor, rudder position sensor,flap position sensors etc. Also as known in the art, the flight controlcomputer connects to aircraft instrumentation as well as aircraftautopilot servos for actuating and controlling the aircraft aileron,rudder, flaps, spoilers etc. Flight control systems including a flightcontrol computer are well known as shown e.g. in U.S Pat. No. 5,714,948,the details of which are incorporated herein by reference.

[0025] Aircraft A also includes a flight control system 20 ashereinbefore described and shown in aircraft B. Remote control ofaircraft commenced with hobbyists and later more sophisticated remotecontrol systems appeared in the patent literature e.g. as shown in U.S.Pat. Nos. 5,067,674 and 3,557,304. U.S. Pat. No. 3,3557,304 isillustrative of a system where a cockpit T.V. camera 11 provides adisplay 16 of panel instruments 22 at the ground station for control ofthe aircraft. The above remote control system of U.S. Pat. No. 3,557,304is incorporated herein by reference and is useful in controlling theflight of aircraft A or aircraft B under conditions unique to thepresent system only where comparator 40 is actively controlling aircraftA in a manner hereinafter described. Aircraft B is not under remotecontrol and is transparent to remote ground control since comparator 40in aircraft B has not detected a pilot command error signal therebyactivating transmitter-receiver 50.

[0026] A pilot actuated switch 120 which may be a manual switch locatedclose to the pilot for easy access provides remote control transfersignal 119 driving a relay closing switches 229 and 230 activatingtransmitter-receiver 50 and providing data transfer through data link 52to and from ground station transmitter-receiver 60 for remote control ofaircraft in the event of pilot selection of ground control of theaircraft A. Pilot actuated switch 120 may also comprise a voice actuatedswitch responsive to a pilot's vocal command. Remote control transfersignal 119 is equivalent to pilot command error signal 117 intransferring control of the aircraft in the present system to groundcontrol. Pilot actuated switch 120 could be alternatively driven byradio control from the pilot in command at the ground station only insystems where it is considered possible that the pilot would beunavailable to actuate pilot activated switch 120 and the aircraft wasconsidered by the pilot in command at the ground station determined fromthe aircraft flight path that the aircraft was flying uncontrolled.

[0027] Turning now to FIG. 2 illustrative of comparator circuit 40 thereare seen aircraft instrument data information signals, signal 29representative of aircraft speed and a further signal 30 representativeof a 2 engine OFF condition for a twin engine commercial jet aircraft.As shown in comparator circuit 40 of FIG. 2, when signal 29representative of aircraft speed exceeds 0.86 mach AND a signal 30representative of a 2 engine OFF condition are provided as inputs tocomparator circuit 40, then a pilot command error signal is provided byAND circuit 98. Pilot command error signal 117 drives a relay closingswitches 229 and 230 activating transmitter-receiver 50 and providingdata transfer through data link 52 to ground stationtransmitter-receiver 60 for remote control of aircraft A. Whilecomparator 40 with the aforementioned input signals 29 and 30 as shownin FIG. 2 for a twin engine commercial jet aircraft clearly illustrateimmediate generation of a pilot command error signal 117 and need forinstant remote control by a ground station to avoid a potentiallycatastrophic incident, it will be recognized by those skilled in the artfrom the foregoing that other combinations of flight data indicative ofincipient need for generation of a pilot command error signal 117 andground control will become apparent e.g. a pair of input signals such asthe combination of low cabin temperature representative of the approachof dangerous interior icing AND an ON autopilot would necessitate groundcontrol. In the above example of pilot command error it is important toobserve that pilot command error signal 117 is generated at the instantthat the twin engine OFF signal appears as an input to comparator 40together with an aircraft speed signal exceeding 0.86 mach, thustransferring control to the ground control and thereby enabling recoveryaction to be taken before the occurrence of further abnormal maneuveringof the aircraft. A further example would be the combination during finaldescent of signal representative of a flight path angle exceeding theflight path angle for the runway and a signal representative of pull upcommands from the aircraft's proximity warning system.

[0028] Turning now to FIG. 3 there is seen a flight control system 41aboard an aircraft in flight and there is also seen an identical flightcontrol system 42 which is located at a ground station and is tested asa standard frequently by ground personnel from the manufacturer of theseflight control systems. Flight control system 41 aboard the aircraft inflight and the counterpart standard flight control system 42 at theground station here are shown in U.S. Pat. No. 3,327,973 and taken forillustrative purposes only since different types of flight controlsystems for various aircraft will require their matching ground stationcounterpart for generation of an equipment substitution signal 224 inthe system of FIG. 3. Transmitter-receiver 50 aboard an aircraft andtransmitter-receiver 60 at the ground station in FIG. 3 correspond totransmitter-receiver 50 aboard aircraft A and transmitter-receiver 60 atthe ground station in FIG. 1. A comparator circuit 140 as shown in FIG.3 looks at output signal 24 of flight control system 41 aboard theaircraft (transmitted through data link 52) and compares the outputsignal 24 with output signal 124 from standard ground control flightcontrol system 140 and if there is inequality causes equipmentmalfunction detection signal 224 to be transmitted via data link 52 toenergize switch 516 to the dotted line position thereby transmittingstandard flight control output signal 124 to autopilot elevator controlof the aircraft in substitution of the flight control output signal 24from the malfunctioning aircraft equipment. It should be noted thatground flight control system 42 receives the identical input signals viadata link 52 as flight control system 41 aboard the aircraft.

[0029] While generation of an equipment malfunction detection signal foran aircraft flight control system has been described, it will berecognized by those skilled in the art that other systems aboard theaircraft may be checked either continuously or periodically with amanufacturers ground system standard depending upon the datacommunication channel characteristics available including bandwidth,data transfer rates and number of aircraft monitored for equipmentmalfunctions by the present system.

[0030] Turning now to FIG. 4, it can be seen that aircraft during flightexperience several configurations including cruise configuration, prelanding configuration and transition configurations prior to achieving apre landing configuration.

[0031] Hereinbefore described was the generation of a pilot commanderror signal 107 based upon recognized known conditions requiringimmediate remote control from a ground station however predictingaircraft behavior and providing aircraft control of maneuvering aircraftdue to various possible equipment and/or aircraft control surfacefailures is beyond the capability of even an experienced pilot undermost circumstances since these are rare occurrences. Behavior of anaircraft under such conditions requires wind tunnel testing, analyticaland computational studies for each of a number of single or combinationsof abnormal configuration flight conditions. Unsteady forces, moments,surface pressures etc. all have to be studied to provide correctcontrols under such circumstances. Occurrences of undesired events suchas stall below glide slope capture in a pre landing configuration allowminimal opportunity for correction and the system of FIG. 5 in contrastis in general directed to recoveries at higher altitudes from abnormalmaneuvering configurations based upon analysis of non-linearaerodynamics. The system of FIG. 5 inputs flight control informationsignals from an aircraft via data link 52 to a control computer 121 atthe ground station which provides output signals to ground flightcontrol 17 for transmission of flight control signals 28 to control theaircraft in flight instead of utilization of ground control computer 21hereinbefore discussed for control under normal flight. Of importance isthe immediate and early detection of flight control information signalsrepresentative of abnormal maneuvering so that control computer 21 canprovide immediate flight control signals 28 for corrective action priorto time lapse and further deterioration of flight control of theaircraft.

1. A method for intervention control of an aircraft in the event of apilot command error whether voluntary or involuntary comprising thesteps of: generating an alert signal representative of a pilot commanderror; and transferring flight control management from said aircraft toa remote ground station in response to said alert signal representativeof a pilot command error thereby providing instant remote control by theremote ground station to avoid a potentially catastrophic incident.
 2. Amethod for controlling an aircraft under maneuvering conditions inemergency situations including loss of a functioning control surfacecomprising the steps of: acquiring flight performance data from anaircraft in flight at altitudes above glide slope capture during amaneuvering condition; and utilizing non-linear aerodynamics to processthe flight performance data for providing aircraft control.
 3. A methodfor intervention control of an aircraft in the event of pilot selectionof ground control of the aircraft comprising the steps of: generating aremote control transfer signal representative of pilot selection ofground control; and transferring flight control management from saidaircraft to a remote ground station in response to said remote controltransfer signal representative of pilot selection of ground controlthereby providing instant remote control by the remote ground station toavoid a potentially catastrophic incident.
 4. The invention according toclaim 1 wherein said step of generating said remote control transfersignal representative of pilot selection of ground control comprisesclosing a pilot actuated switch or a voice activated switch.
 5. Incombination in an aircraft: a pilot actuated switch for providing aremote control transfer signal representative of pilot selection ofground control of the aircraft; a transmitter-receiver responsive tosaid remote control transfer signal representative of pilot selection ofground control of the aircraft; and said transmitter-receiver providingdata transfer through a data link to and from a ground stationtransmitter-receiver for ground station control of the aircraft.
 6. Thecombination according to claim 5 wherein said pilot actuated switch isdriven by radio control from a pilot in command at the ground station inresponse to uncontrolled flight of the aircraft.